In recent years, a wireless communication system has been widely spread that collects, through wireless communication, information acquired in various apparatuses and utilizes the information. For example, there is known a probe car system that acquires information such as a driving situation and the like of a vehicle from various sensors in the vehicle. There is also known a sensor network system that includes sensor-equipped nodes scattered in the sensor network system and acquires sensing results from the sensor nodes.
In such a system that collects information, if all the nodes transmit acquired all data, excessive traffic occurs. Therefore, it is conceivable to transmit only necessary information.
For example, Patent Literature 1 discloses that a portable game apparatus establishes a communication state between the portable game apparatus and another game apparatus and, thereafter, the game apparatuses transmit and receive an exchange condition for exchanging game data and, when the exchange condition is met, exchange the game data.
Patent Literature 2 discloses that a wireless base station transmits a transmission request (analysis target determination data) including a predetermined condition (a filtering condition) and vehicle-mounted terminals transmit data only when the predetermined condition is satisfied. It is likely that interference occurs if all the vehicle-mounted terminals are called all at once. However, the interference is prevented by selectively calling only a part of the vehicle-mounted terminals in this way.
In both of Patent Literature 1 and 2, necessity of transmission of data is determined on the basis of information transmitted from a communication partner. Patent Literature 1 and 2 are based on the premise that wireless connection between transmission and reception nodes is established. However, in a system that does not establish wireless connection at normal time and establishes the wireless communication when transmitting data, there is a problem in that, if necessity of transmission is determined by the methods of Patent Literature 1 and 2, useless wireless connection occurs. That is, after wireless connection is performed to acquire subscription information, when it is determined that data transmission is unnecessary, establishment process for the wireless connection is wasted.
Patent Literature 3 discloses that, in a wireless USB system, attribute information indicating as which of a host side and a device side an apparatus itself is operating is included in a beacon and transmitted. Consequently, a wireless USB-adapted apparatus can grasp, simply by receiving the beacon without exchanging complicated commands, as which of the host side and the device side the apparatus is operating.
In the method of Patent Literature 3, by including the attribute information in the beacon and transmitting the attribute information, it is possible to transmit information without establishing wireless communication. However, in the method of Patent Literature 3, even if the apparatus itself receives the beacon, the apparatus itself cannot grasp whether a transmission destination needs data owned by the apparatus itself.